Mobile stations may be equipped with stereo speakers for use in various applications. Such stereo speakers may operate in conjunction with a tilt sensor or position detecting sensor, to enhance three-dimensional (3D) game applications, for example.
However, even if various applications using a tilt sensor or a position detecting sensor are provided in a mobile station, a technique for controlling a stereo speaker by using the tilt sensor or the position detecting sensor is not provided. Thus, control of stereo speakers that operate in conjunction with a tilt sensor or position detecting sensor is needed.